Control Description; Ok Relay; Precharge Enabling Control; Mlp Signal - gefran SM32 Manuel D'instruction

4. Control description

4.1. OK Relay

The OK relay has a normally open contact which close at the end of the precharg-
ing phase if no alarm condition is present (overtemperature, power supply on the
regulation card ±15V).
The contact is closed during the normal functioning of the device and also during
an undervoltage situation. The contact opens when a failure occurs (see the alarm
conditions described above) or when the power supply is switched off and the DC-
Link is completely discharged (C and D terminals).

4.2. Precharge Enabling Control

Such input allows to delay the precharging phase with respect to the moment in
which the power supply (U,V,W terminals) is applied.
The precharging phase occurs supplying terminals 23 to +24V, available on the
terminal strip, (common on terminal 52).

4.3. MLP Signal

The MLP signal is a digital output available on the terminal 32.
This signal is a sum of the undervoltage threshold (via S2.1-3 set) and the pre-
charging phase.
It will be LOW with a 0.5ms delay after the undervoltage threshold is reached.
The digital output will be again HIGH, at the end of the precharging phase. This
sequence is repeated at every mains dip (see chapter 6.2 figure B).

4.4. ML Signal

The ML signal is a digital output available on terminal 36. It is the AC mains volt-
age monitoring.
With "CV" jumper mounted (ON), the ML signal will be LOW when the undervolt-
age threshold is reached.
The digital output will be HIGH when the voltage is above the threshold (see the
above table).
With "CV" jumper not mounted (OFF), the ML signal will indicate, with a 150mS
pulse, an undervoltage value transition.
When the voltage comes back above the threshold value, this will be not revealed
by the ML signal (see chapter 6.2 figure B).
36
SM32 • Instruction manual